I don't believe the fake-to-third-throw-to-first will be considered a balk if the pitcher is not in contact with the rubber because if you're not on the rubber, you're even allowed to fake to first or second. I don't know how the play ever became legal for pitchers who were in contact with the rubber, but sometime in the 1970s or '80s, umpires stopped calling balks on the play.

__________________It breaks your heart. It is designed to break your heart. The game begins in the spring, when everything else begins again, and it blossoms in the summer, filling the afternoons and evenings, and then as soon as the chill rains come, it stops and leaves you to face the fall alone. - A. Bartlett Giamatti

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Maybe I'm reading this wrong, but it's not just the 3rd to 1st move, but any fake throw to third by the pitcher. This seems like a horrible idea to me. Fake pickoffs to third are a part of the game for a reason, runners are going to be running wild in first and third situations. The pitcher is already at a disadvantage having to hold two runners from advancing.

Maybe it's me getting old, but whenever I see this move done, I think of Blackjack. He seemed pretty good at it.
So basically if you're a runner at first, as soon as the arm motion goes to third, take off for second? Seems to me this will reward teams with speed and aggressive base running. Sounds like a good fundamental to practice in spring training.

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Do the white sox know that it is Designated Hitter, not Designated Out?

Maybe I'm reading this wrong, but it's not just the 3rd to 1st move, but any fake throw to third by the pitcher. This seems like a horrible idea to me. Fake pickoffs to third are a part of the game for a reason, runners are going to be running wild in first and third situations. The pitcher is already at a disadvantage having to hold two runners from advancing.

There they go watering down the game again to the detriment of pitching, anything to pump the scoring now that PEDs on the way out. Honestly I wish they'd put the height of the mound back up where should be too. That fake 3rd pick off is thriller when it works. Once I was pitching,pulled that move, but the 1st baseman was fooled and was not expecting the throw to come to him, 2 runs scored, oh no. So it has its risks too.

I was watching Dan Pleasac and someone else discuss this on MLB Network a few weeks ago and Pleasac pointed out that prior to 1986ish the fake to third go to first move WAS a balk, so this isn't that big of a rule change.